CPC is Fifth generation protection and control system. CPC
system is comprised of high-performance computing platform(s) capable of
providing protection, control, monitoring, communication and asset management
functions by collecting the data those functions require using high-speed,
time synchronized measurements within a substation.†

As shown in block 5, IMU sends voltage and current
sample values to CPC using 61850-9-2. Process unit status monitoring and its control
is also done through IMU.

IEEE Power System Relaying and Control (PSRC) WG K15
documents on CPC: